System and method for cardiovascular health monitoring

Abstract

As shown in FIG. 1 and FIG. 2 , the health monitoring system 100 of one embodiment includes an electromagnetic transmitter 110 configured to transmit an electromagnetic signal towards a target body region on a user; an electromagnetic receiver 120 configured to receive reflected energy from a target body region on a user; a calibration sensor 130 that measures reference cardiovascular-related parameters of a user (such as vessel pressure, stiffness, or motion); and an activity sensor 140 configured to detect the activity state of a user. The system also includes an attachment mechanism 150 for fixing the electromagnetic transmitter, electromagnetic receiver, calibration sensor and activity sensor to the user; and a stand-off mechanism 160 for fixing the electromagnetic transmitter and electromagnetic receiver at a known standoff distance from a target body region on the user.

The invention claimed is: 
     
       1. A wearable system for measuring an arterial pulse waveform of a user, the system comprising:
 a radio frequency (RF) electromagnetic transmitter for transmitting an RF signal having a frequency in the range of 30 GHz to 300 GHz towards a target body region on the user, said target body region being skin over an artery of the user; 
 a radio frequency (RF) electromagnetic receiver for receiving reflected RF signals from the target body region; 
 an attachment mechanism that is adaptable to position the RF electromagnetic transmitter and the RF electromagnetic receiver proximal to the target body region and to maintain the position of the RF electromagnetic transmitter and the position of the RF electromagnetic receiver relative to the target body region; and 
 a stand-off mechanism for positioning on the user an antenna for the RF electromagnetic transmitter and an antenna for the RF electromagnetic receiver such that a standoff distance from the user's skin is within a range of between 1 mm and 20 mm for each of the RF electromagnetic transmitter and the RF electromagnetic receiver, wherein the standoff mechanism is configured to substantially avoid perturbing the physiology of the target body region and enable the user's skin and tissues overlying the artery to move freely with respect to the RF electromagnetic transmitter and the RF electromagnetic receiver; 
 wherein the transmitted RF signals and received RF signals are coupled into a processor to form a radar system, and 
 wherein the processor comprises an operating mode in which the processor is configured to generate a blood pressure dataset based on the received RF signals, said blood pressure dataset containing data pertaining to the user's arterial pulse waveform. 
 
     
     
       2. The wearable system of  claim 1 , further comprising an enclosure, wherein the enclosure houses the RF electromagnetic transmitter and the RF electromagnetic receiver. 
     
     
       3. The wearable system of  claim 1 , further comprising a guiding structure to influence at least one property of the received reflected RF signals. 
     
     
       4. The wearable system of  claim 1 , wherein a guiding structure is arranged between at least one of the group consisting of: the RF electromagnetic transmitter and the target body region, the RF electromagnetic receiver and the target body region, or both of the RF electromagnetic transmitter and receiver and the target body region. 
     
     
       5. The wearable system of  claim 1 , further comprising a calibration sensor that measures at least one cardiovascular parameter of the user, wherein the processor comprises: a calibration mode, wherein in the calibration mode the processor is configured to receive a set of input parameters based on the measured at least one cardiovascular parameter of the user from the calibration sensor, and wherein in the calibration mode the processor is configured to output a set of calibration parameters. 
     
     
       6. The wearable system of  claim 5  wherein in the operating mode the processor is configured to generate the blood pressure dataset based on the received reflected RF signals and the set of calibration parameters. 
     
     
       7. The wearable system of  claim 1 , wherein the system further comprises an activity sensor for detecting motion of the wearable system, and the system is configured to determine whether a detected motion level of the wearable system is below a threshold motion level prior to triggering operation of the system to measure the user's arterial pulse waveform. 
     
     
       8. The wearable system of  claim 1 , wherein the system further comprises an activity sensor for detecting an activity state of the user, and wherein the processor is configured to generate a contextualized blood pressure dataset based on the activity state of the user. 
     
     
       9. The wearable system of  claim 1 , wherein the radar system is a frequency modulated continuous wave radar system. 
     
     
       10. The wearable system of  claim 1 , wherein the radar system is a doppler radar system. 
     
     
       11. The wearable system of  claim 1 , wherein the radar system is a pulsed radar system. 
     
     
       12. The system of  claim 1 , wherein the standoff distance for the RF electromagnetic transmitter is different from the stand-off distance for the RF electromagnetic receiver. 
     
     
       13. The wearable system of  claim 1 , wherein the standoff mechanism comprises a curved shape. 
     
     
       14. The wearable system of  claim 1 , wherein the processor is wearable along with the other components of the wearable system. 
     
     
       15. The wearable system of  claim 1 , wherein the standoff distance from the user's skin is within a range of between 4 mm and 10 mm for each of the RF electromagnetic transmitter and the RF electromagnetic receiver. 
     
     
       16. The wearable system of  claim 1 , wherein the standoff mechanism is configured such that the target body region remains outside of the reactive near-field region of the RF electromagnetic transmitter and the RF electromagnetic receiver.